Hey all,

Doing some research (started on facebook) on which bluetooth OBD2 modules

BLUETOOTH OBDII BATTERY DRAIN ISSUE?
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Update: Current Results - keep them coming!
#1 BAD - causes draining (2 reported)
#3 BAD - causes draining (1 reported)
#4 GOOD - no problems reported (1 reported)
#5 GOOD - no problems reported (1 reported)
#6 Mixed results? Both good and bad reports (1 BAD, 2 GOOD reported)
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Trying to find a Bluetooth OBDII Module that does not drain battery after disconnect (known F-Type Issue). If you have one that you know does or does not drain the battery, can you share what it is in the comments?

Wondering if we can find one (maybe higher quality or different manufacturer, or particular function) that does not cause this battery drain issue.

NOTE: The image just shows the most popular Bluetooth OBDII modules that I found on Amazon, and does not show them all, and some appear to be re-badges of the models shown below. Feel free to let us know if yours isn't listed, and if it causes the issue (maybe provide a link?)

Thank you for helping figure this out! (p.s. MODS - I misspelled bluetooth in my title, possible to fix?)

 

I have a rebadge of #1 - and it drains the battery after disconnecting it.

 

Pardon my ignorance, but what do those things do?

 

OBD = On Board Diagnostics. Your mechanic uses it to get codes from the car to assist in fixes.

At the consumer lever (which is what the bluetooth modules are for), consumers can use them to help diagnose issues with their own car, as they are used to show error codes thown by the car (when your check engine light comes on, you can use this to tell you why).

Additionally, OBD2 provides real time information like RPM, etc that you can use with an app like "Torque" to display cool information: https://play.google.com/store/apps/d...l.torque&hl=en

 

I have a lot of experience with these, as a side business.

Some of those adaptors do not have "low power mode". However that is ONLY relevant when you are leaving it plugged in 24/7. Any new stock of the adaptors has low power mode. But again, really not relevant.

"After disconnect" -- it is a problem with the *car*, not the OBD adaptor.

THAT SAID -- I press the "disconnect" button on the device I use to close the connection with the car, before I unplug it. I don't know if that helps, but "closing" the connection in software would make sense and it may be a way to signal to the car that you want it to go to sleep.

If there is a way to tell these adaptors "close the diagnostic session" *between it and the vehicle*, then that may be a solution.

There's a command to issue to the powertrain control module to "close connection". All of my software and hardware issues that command. Given that some of these devices are under $10 and the software is $3, it would not surprise me to find out they did not design the software with that in mind, but I'm not familiar with all products out there.

I use many similar adaptors (in fact I do testing on the F-Type) and have no problems, but I always tell it to close the diagnostic session with the vehicle.

 

15FTypeR - Thank you for the insight!

We've actually been trying to come up with theories, and someone on Facebook did mention that it was the "Car" not the adapter, but we did have one person who had a couple of different adapters - one caused the problem, and the other works without issue.

Now with your solution, are you stating that *any* bluetooth adapter should work provided you disconnect your device from the adapter before removing the adapter from the car? Is that like: Going into phone settings and stopping bluetooth, or do I look for a "stop" button in my app (say "Torque")? Or do I swipe the app shut on my phone?

I have one of the adapters that I just assumed was bad, but I will try it to see if it causes the issue - so long as I know exactly what you are doing. Do you use Torque? or what app do you use?

Again, thanks for your input!

 

I have suspected for awhile now that the shutdown sequence will determine whether the battery management module gets confused, but I have been too busy (call it lazy) to sort that out. It's easier to just disconnect the battery for a few seconds if the Hazard button light stays lit too long.

 

Ug! I got tired of disconnecting the battery after each one and losing settings (whatever it was that was erased) so I stopped using it all together. But if I can find a way to make it work without having to disconnect the battery, I am all for it, and I would use it all the time.

 

The adapter maintains a "conversation" with the car... and a conversation with the device (phone). Just disconnecting your device (phone) from the adaptor, might not make the adaptor close the conversation with the car. It depends on what they did with the firmware. GOOD design would dictate that the adaptor should close the conversation with the car when the device disconnects but I can tell you for sure that they do not in most cases. The software (on your phone) must tell the adaptor "close the connection to the vehicle". Also, just turning off the ignition before "close the conversation" is received may not let the powertrain control module sleep. GOOD design would time out after a while. It seems the F-type didn't get this right.

 

@15FTypeR - You stated that you press the 'disconnect' button on the device.

What devices in particular are you using? Are you using bluetooth OBD adapters with a phone? If you are using multiple devices, what are they? Do your devices use bluetooth to communicate - or are they self contained. For example: Right now I am under the assumption that if you are using bluetooth, the problem is "possible". If you are not using bluetooth, the problem does not exist.

I have a plan to run through several scenarios testing a couple different OBD adapters (cheap and more expensive), as well as a VSwitch that I know closes the "connection" (like checking if the Vswitch can close a connection left open by a OBD bluetooth module, etc), so that I can try and narrow down and figure out exactly what will close the conversation properly.

You have obviously been successful in avoiding the problem all together so it would be good for me to know the devices and processes you use. If I have any of the same "devices" that you are using, I want to see if my results match yours or if there are disparities between my car and your car. Also, do your devices fall under the "uses bluetooth to communicate to a head unit (i.e. Phone)" or are they self contained units where the controller is connected by wire?

Anyhow, the more information I can get before I do my testing, the better.

 

Clarification:

I press a button that causes the software/firmware to properly close the conversation with the car. You do not have any of the same devices that I have because they run my custom software.

 

Fair enough, but does your device connect directly to the OBD2 port via a cable/wire or is it bluetooth?

 

They are wired however they could be wireless too... Let me explain that better...

Bluetooth, wifi, or wired do not matter really because the vehicle interface side on all of these is the same. It's really a two part interface.... 1) vehicle side and 2) phone/wifi/bluetooth/USB side with a middleman translating between them. The software (talking to the #2 side, for example Torque) needs to tell the vehicle side to properly close the conversation. I have some wifi and bluetooth devices that I can do some testing on and see how or if they cause problems and test my theory about the importance (or not) of closing the session with the vehicle.

I've seen that a lot of these cheap systems do not end the conversation with the vehicle properly, instead just "dropping" it or letting time out, or worse, doing nothing, and it isn't terminated until you physically pull the plug from the car, or the car gives up talking, etc. None of that is the optimal method, given that the f-type doesnt seem to know when to sleep. I'll report my findings...

 

If my car gets stuck in battery drain mode, how will I know? The hazard light button stays lit indefinitely?

When I exit torque, it closes quite abruptly. Did it send the command to close comms? I will not know without connecting something inbetween to capture the data. Torque will not let me output a debug log to myself - only to them, it seems. Maybe someone should contact Torque and ask.

As for the "good/bad" reports, I don't think 1 or 2 accounts is enough to be labeling them like you have, especially when 1) the car is the actual problem, AND 2) we don't know if the user was operating the device correctly. It's your thread though...

 

The size of the data pool is determined by who participates, and in my opinion 1 case is better then none, 2 is better then 1. We are still taking information from anyone who is willing to offer it. I have no other way to get the information unless I do it myself. Point of the forum is collaboration. We are simply trying to find a solution.

I realize that you already have assumptions that whatever we do, we aren't going to figure out anything, but you still seem to be willing to help. You are are in a somewhat unique position to help because of the tools that you have used.

I have asked you about being cabled or bluetooth - which you say doesn't matter, because it is the car that is the problem. Well I have my own cabled device, and I know several others with cabled devices that do not cause the problem (including accounts form you saying that you haven't had the issue). THose same people have bluetooth devices that DO cause the issue. To me so far, that is the start of building a thesis that maybe is has something to do only with wireless devices. Maybe? We can trash this theory once we have reports of wired devices causing the problem - but we don't as of yet.

I also have information from several users on the wireless (bluetooth) devices that they are using, and though it is a small sample, it appears that the devices that advertise that they have a 'sleep function' do not cause the battery drain. The ones that do not advertise that they have a sleep function are causing the problem (even after disconnected) - now this is a small sample, but it is a theory of one of the guys on facebook, so it is one thing we are testing.

Again, you've stated that you think its the car. Well, we have someone that has 2 different bluetooth devices - one causes the problem, the other doesn't. One has the sleep function, one doesn't. I believe that is relevant.

As we get more and more people to share their experiences we can develop theories and start to test them. If we just decide that the data isn't worth pursuing because we don't know if the user obtained it correctly, then we can just give up now.

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Moving on to your other post, because it seems like you want to help (and I hope you do), YES, we feel with the data that we have so far that if the hazard light stays on past the point when the car goes into sleep/hibernation then that is a definitive indicator that the battery is still being drawn on. I am not sure how long we have to wait for it to go off but right now I think 5 to 10 minutes is sufficient (more testing will narrow this down).

Again, I would love to get your input on several factors - and I do believe they are helpful.

If you have any of the wireless devices above - which one(s)? Which ones cause the issue, which do not? If you can get one to cause the problem, then do something different (i.e. turning off the communication) with the app controlling it and have it not drain the battery - we would love to know what that is.

If you have wired devices, I assume that you have never had the problem with them, but if I am wrong - let me know. I have a wired device that I have disconnected in multiple ways - and can't get it to drain the battery. Alternatively, I have #1 in the image above and haven't found anything that will stop it from draining the battery.

Any information that anyone can provide on their own experiences (making sure it is accurate to the best of their ability) will be helpful. And obviously we will post our results to try and help people make the best possible decisions when using anything with the OBD port.

 

I'll clarify further ScubaAddict.... The cabled devices typically have a "disconnect" button since there is more advanced software involved, or a built in screen, whereas the wireless ones do not and mostly rely on $3 software. Software needs to issue the command. What I'm saying is the graceful disconnect could possibly be the problem. The wire, is just a coincidence. Having improper communication to the car may be an issue as noted. Hopefully this is much clearer now.

I don't want to draw any conclusions one way or the other without more info, is all I'm saying.

If you have many times yanked the cable while a cabled device is actively "talking" to the F-type, then you have effectively tested (and disproven) the theory of "no disconnect command = bad" in my opinion. Presence of a wire is immaterial. Proper design of the device and firmware is what matters. If you've done that, then like I said we can probably ignore the "disconnect" question.

Nearly all (or possibly all) of those devices pictured I know are ELM based. Could it be ELM related? There are wired interfaces using he same ELM interface as those wireless ones. There's probably 100 different ELM-based devices on the market all with different stickers on them.

On the other hand (see what i did here?), handheld devices with their own screens which are on the market, are usually not ELM based. Is that what you meant when you said "wired"?

I've tested the Autel Maxidiag Elite (has its own screen) on my jag, a couple times, and it did not cause problems. Works well btw.

I have a couple of the devices there which I collect out of curiosity. I have not tested those on the jag but I've tested them on a hyundai. I'm not really willing to test them on the jag until I know more about how to see if the car is reacting wrong (you explained above, thanks), and I want a better answer how to correct it because I'm not disconnecting my battery and losing who-knows-what crap in the interest of testing $10 gadgets which reportedly cause issues on my expensive car. LOL alas my hyundai does not have the f-type's problem.

Again my experience with other systems is that they are careless about "disconnect". It should not matter, but it might to the f-type. That's the basis for my theory, and I'm not running with it until I have collected some more info. Theory may be wrong. I'll discuss it with Torque, instead of guessing or relying on anecdotal evidence collected from people I don't know, not even by my sample of 1 (myself)... Incorrect or limited data are a problem-solver's enemy. I'd really rather talk to the engineers at torque about this before theorizing further about it. When I have the opportunity to do that, I'll report back.

As for what people are gathering, thats fine, people can talk all they want, and they'll always draw conclusions. Again, I'm not comfortable with putting the word "bad" next to anything, any product produced or distributed by anyone, with a sample size of 2 opinions. This is how religions get started haha.

 

If you put on a device that causes the battery drain problem, the only known way of fixing the problem (stopping the battery from draining) is to disconnect and reconnect the battery. Otherwise you will get low battery warnings on your dash and your battery will die within a couple of days. Disconnecting the cable (to stop the issue once it has started) will wipe out some settings - but I do not remember exactly which ones - maybe someone else in here knows which ones are effected ( I think it is radio stations and time setting, maybe more). I completely understand that you may not want to deal with having to disconnect the battery, and I totally understand.

I understand what you are saying about having to disconnect communication before disconnecting the device, and this is not contrary to what we are trying to test. There is no opposition to your theories. Being a problem with the 'car' may indeed be true, but we are pretty sure there is a way to avoid it, and that is what we are trying to discover. In addition, we are attempting to find an easier fix then disconnecting the battery should you happen to run into this issue.

I just purchased #7 and plan to carry out multiple tests, testing multiple theories once it arrives, so I am trying to get as much info from the community prior to that - hence my original post. I will be testing:

#1 does the obd2 module cause the issue? (It has sleep mode, my other 2 devices do not)
#2 if placed in battery drain mode, can I recover by connecting a different (possibly a wired OBD device or the new wireless device) device known to "close the connection", hopefully eliminating the need to disconnect the battery.
#3 how long do we have to wait for the hazard light to go off before we can conclude that it is in battery drain mode.
#4 is there any way to disconnect a "seemingly" bad device in a manner that will stop it from draining the battery (i.e. find a way to "disconnect" or close the communication that may not have been explored in the past - i.e. using a 'disconnect' button if available, or turning off bluetooth first, or 'swipe-off' the app before disconnecting the module from the car).

Any other theories that people propose that would be useful to others, I can try setting up a test for that as well.

No matter what results that we find it is going to be very helpful if others who have plugged any device into their OBD port can provide us with what it was (exactly) and an account of any battery drain issues they have had (yes or no). We have someone who has a HUD device that plugs into the OBD - we are waiting on his experience. We have multiple accounts of a Vswitch plugged into the port. We know that many Wired OBD units do not cause the problem - regardless of hitting a "disconnect switch" before disconnecting them.

So we are still open to everyones experience with OBD devices - let us know by replying!

 

#7 is from a company that's been around a long time. I think they'll be interested to hear your findings and might even want to help with a workaround if there's a problem.

I edited my post BTW, probably after your reply. Possibly more useful bits in there for your info gathering.

Sounds like you have a good plan for collecting the pertinent details there. Sorry if I sounded discouraging at first.

 

I've got both a hardwire device and a WiFi device which in the past have caused the issue. More recently, and since an infotainment update, the hardwire device does not trigger the issue, but I might have changed my disconnect sequencing over time which may be the reason instead. I have not used the WiFi device since the infotainment update was done. I won't offer anymore theories until I've had a chance to do much more testing with these two devices.

 

No worries, sorry I got a little defensive. This has been a frustrating issue for me. I'm just glad I've found others who are also frustrated and want to find a work-around.

Scantool does seem to be one of the better manufacturers - at least by their own proclamations, but looking at reviews they are not very responsive to customers and support issues, refering people to their forum. It is an issue that doesn't effect very many people in general, much less in their customer base. I guess we will see what happens with testing and go from there.

Unhingd - thanks for the input. Does anyone know how someone might be able to check if they have received this 'infotainment' update? Also, when did it become available?